a visitor to the visit the actual default value of this
annotation interface method, or null if this visitor
is not interested in visiting this default value. The 'name'
parameters passed to the methods of this annotation visitor are
ignored. Moreover, exacly one visit method must be called on this
annotation visitor, followed by visitEnd.

visitFrame

Visits the current state of the local variables and operand stack
elements. This method must(*) be called just before any
instruction i that follows an unconditionnal branch instruction
such as GOTO or THROW, that is the target of a jump instruction, or that
starts an exception handler block. The visited types must describe the
values of the local variables and of the operand stack elements just
beforei is executed.

(*) this is mandatory only
for classes whose version is greater than or equal to
V1_6.

Packed frames are basically
"deltas" from the state of the previous frame (very first frame is
implicitly defined by the method's parameters and access flags):

Opcodes.F_SAME representing frame with exactly the same
locals as the previous frame and with the empty stack.

Opcodes.F_SAME1
representing frame with exactly the same locals as the previous frame and
with single value on the stack (nStack is 1 and
stack[0] contains value for the type of the stack item).

Opcodes.F_APPEND representing frame with current locals are
the same as the locals in the previous frame, except that additional
locals are defined (nLocal is 1, 2 or 3 and
local elements contains values representing added types).

Opcodes.F_CHOP representing frame with current locals are
the same as the locals in the previous frame, except that the last 1-3
locals are absent and with the empty stack (nLocals is 1,
2 or 3).

getLabelNode

Returns the LabelNode corresponding to the given Label. Creates a new
LabelNode if necessary. The default implementation of this method uses
the Label.info field to store associations between labels and
label nodes.